Welcome to FABO, by the serial number provided, 8B125822 would be a 1968 model car made in Hamtramck with the last digits of 125822 which would match the last 6 digits of the car's V.I.N. that it came out of.
On a '68 model car, these numbers would have been stamped on the top of the block where the engine and transmission bell housing would meet near the top of the engine.
I'm not sure of the other numbers except some of the transmission numbers which are PP8332175-0018 which would be a 4 speed manual transmission (833) 2175 is the date code (which I'm not sure of), and 0018 is the 18th transmission assembled that day.
I hope this helps you, and I hope others will chime in.
And in 1968, the engine would have come from a Charger, Coronet, Plymouth Road Runner, or GTX with the slim possibility of it coming from a Dart or Barracuda Super Stock car, but it was unlikely that the V.I.N. of the car was stamped on the engines of these cars.
Wow, I wish I were in your shoes...
